1. Field of the Invention
The present invention relates to a solid-state imaging apparatus and camera.
2. Description of the Related Art
A solid-state imaging apparatus can include a photoelectric conversion portion, a floating diffusion (to be referred to an FD hereinafter), and a transfer transistor which transfers charges generated and accumulated in the photoelectric conversion portion to the FD. A signal corresponding to an FD potential is obtained as a pixel signal from the solid-state imaging apparatus.
Japanese Patent Laid-Open No. 2011-049446 discloses a back-side illumination solid-state imaging apparatus in which an FD is provided in the center of a pixel region, a photoelectric conversion portion is provided on the periphery of the pixel region so as to surround this FD, and the gate electrode of a transfer transistor is formed annularly.
According to the structure disclosed in Japanese Patent Laid-Open No. 2011-049446, since photoelectric conversion is also performed in the FD, the FD potential changes before a charge is transferred from the photoelectric conversion portion to the FD. This reduces a dynamic range. For example, when a luminance is high, the output from a pixel or a readout unit which reads out the pixel exceeds its saturation level.